Portable media players are designed to play media files that are stored on either a hard disk drive or flash memory (a non-volatile solid-state memory) found within the case of portable media player. For many users, this internal memory is sufficient to provide the media player with enough media content to meet their needs. Some media players also have an expansion slot that allows certain types of external flash memory to be attached for the storage of additional media files. For instance, a player may have a microSD slot that allows flash memory cards using the microSD format to attach to the media player. This external memory is used to expand the amount of memory usable by the player, thereby allowing users to store additional media files on their media player.
Media files are typically stored on the internal and external memory of the media player using the same type of file system used in personal computers, such as the FAT32 file system by Microsoft Corporation or HFS Plus by Apple Inc. To make accessing these files easier, most media players provide a visual user interface that allows users to browse through and select their desired files. In some cases, the player simply allows users to traverse the files using the file system hierarchy in which they are stored. Other players establish a database that allows users to use metadata relating to the media files to organize and access their media files. For instance, songs may be organized according to genre, artist, title, album, or user ranking. The metadata is added to an internal database that the media player utilizes to assist in user selection and organization of the media files.
Much of the metadata used to create the internal database is stored in the media files themselves. To populate the database, the music files stored on the media player are scanned and the metadata within the file is added to the media player internal database. With some players, this scanning occurs only when the media player is connected to a personal computer. Software on the personal computer is responsible for maintaining the content of the media files on the media player. The personal computer software creates the media player internal database during the synchronization process that takes place when the media player is connected to the personal computer. In these environments, the media player will only play media files that have been added to the memory of the media player by the personal computer software. Consequently, the media player never needs to create or update its internal database—it can rely entirely on the database created by the personal computer software.
Other media players are more flexible as to how the media files can be loaded on to the media player's memory. Consequently, they cannot rely purely on the database created by the personal computer software. Instead, the media player creates the internal database by scanning the media files using the file system of the storage media.